Hypofractionated Radiation For Prostate

Hypofractionation is a form of external radiation therapy that uses fewer, larger doses per fraction. Historically, the conventional radiation dose for most solid tumors is 1.8 to 2 Gray per day. (Gray is just the scientific term to measure the dose.) That conventional dose comes out of the French school of radiotherapy that dominated radiotherapy in the 1940s and 1950s and made its way over to the United States. Most patients treated with external radiation therapy for prostate cancer in 2016 are treated five days a week for eight or nine weeks.

There is some evidence that fewer, larger doses may, in fact, be better. Some studies have been designed to prove that hypofractionation is better, but the results of several studies have failed to demonstrate that theory. Other studies have been designed to determine if hypofractionation is “no worse than” conventional fractionation; these are known as noninferiority studies. Noninferiority studies are used to show that we can accomplish the same objective with a shorter, more convenient treatment.

I’ve just published a paper in the Journal of Clinical Oncology (April 2016) showing that you can accomplish the same thing with hypofractionation in five and a half weeks versus eight and a half weeks. There is another study from the United Kingdom, which was published in June 2016, which shows that you can accomplish the same thing in a four-week schedule that you can with an eight-and-a-half.week schedule. The results from all of these noninferiority studies are consistent: they show that you can accomplish the same objective in four or five weeks versus eight or nine weeks.

Another hypofractionation approach is stereotactic body radiation therapy (SBRT), which is an example of extreme hypofractionation. You get four to five treatments over a period of one to two weeks rather then four to five weeks. This is an emerging approach. We’ve been doing SBRT at Duke University since 2009 and I think it is safe, but it has yet to be compared to more traditional treatment in a rigorous manner. To repeat, we don’t have rigorous comparisons of SBRT to other definitive radiotherapy options, but they’re forthcoming.

Is a shorter course better for patients just for financial reasons, or is it also just more convenient?

Shorter courses are unambiguously more convenient for patients; in 25 years of practice I have never had a patient request longer courses of treatment.

Do patients usually travel to a radiation therapy center?

Yes. I tell men that, “We’re working on it, but we still haven’t figured out a way to bring the machine to you. You have to come to the machine.” There are significant economic advantages with shorter courses as well. In our current healthcare system, value is increasingly important. If you can accomplish the same thing with fewer resources, less time, and more patient convenience, then that is something you should do.